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19th Century Airship Technology for Port Security
fenimor writes "Airships - known today mainly for advertising flyovers at football games - are the core of a new coastal surveillance system in development for the the U.S. Department of Defense. These
stationary platforms 25 times the size of a Goodyear blimp will be equipped with an array of cutting-edge equipment for remote sensing, communications, and risk analysis, providing surveillance coverage over a surface area of 500,000 square miles from an altitude of 70,000 feet."
Currently the USCG employes a pair of blimps "Fat Albert" on Cudjoe Key to watch for dope smugglers, air traffic, etc.
Ob: SovietRussia: For Soviet Russia YOU spy on the blimp!
A feeling of having made the same mistake before: Deja Foobar
It really is SO obvious that they need to put some giant laserbeams on this shit.
I can find out where they are and have the option of not being tracked I'm ok with this. Otherwise we just have Big Brother gone lighter than air. -I
If a terrorist has the know-how to build an air rifle that has a range of 14 to 16 miles then he's probably going to be going after some other targets.
I for one welcome our new blimp-borne overlords (There! I had to say it!).
cheap labor conservatives - they want to keep you hungry enough to be thankful for minimum wage.
So now we have even more national security data that we can't monitor in real time. What good is all this info supposed to be if we can't use it to stop a problem before it happens? Technology is great at recording, storing, and retrieving information, but I don't see a database server walking down to the beach to make an arrest. Are the politicians considering an increase in the Coast Guard, Port Authority, and other applicable agencies? If not, all this new technology won't do much good.
Dosn't this seem terribly innefficient? I mean, mantaining these things in the air at all times, to do a job that seems to already be done by survelience satellites, airplanes and ground. And how does this reduce the risk to terrorism?
Also, what if it gets punctured or damaged while at 70,000 feet? Will there be an immediate action plan to send up a replacement? As it's unmanned, I guess this means that every little defect requires a ground-based overhaul?
Personally, I don't see it working at the moment.
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A terrorist with a really big slingsghot.
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Whew! Total safety is so close I can taste it! Thanks, guys. Without your cameras everywhere, we'd all be blown up tomorrow. (Well, I'm not sure the one in my bathroom is necessary, but I do store bleach there and it could be used as a weapon if terrorists break into my house.)
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Conventional arms can't easily hit a target a few thousand feet above you, let alone SEVENTY thousand feet.
Even fighter jets have trouble exceeding 50-60 thousand feet IIRC. Only specialized aircraft (Scaled's White Knight is one such example) can reach these altitudes.
retrorocket.o not found, launch anyway?
There are much cheaper alternatives in the works, such as the High Frequency Surface Wave Radar being developed by Raytheon Canada and Defence Research Development Canada.
The big problem with conventional radar is that it only works in line-of-site, but Raytheon's SWR-503 Surface Wave Radar uses high-frequency radar waves that "wrap" around the curvature of the earth. The system has been proven to detect and track aircraft, surface vessels and icebergs out to 500 km from the shore in a sector of up to 120 degrees. Suspicious objects can be investigated by satellite, surface ship, patrol aircraft or very cheaply & covertly via unmanned drone.
Canada plans to install an array of radar installations along the East Coast in order to provide a seamless picture of all maritime activity occuring in the country's economic zone. Similar research is being carried out in the US, Australia and other countries. This seems like a much more effective use of resources than a massive blimp installation
When you have nothing left to burn you must set yourself on fire
Astronomers have occasionally used balloon borne telescopes for getting above most of the atmosphere, as it is much cheaper than a satellite. If there is a mass-produced long duration stratespheric balloon/airship available, it could make this much more viable.
As an aside - the article also discusses "Terahertz imaging." One terahertz corresponds to wavelength of about 0.3 mm or 300 microns - extreme IR, or short sub-millimetre, depending on your point of view.
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What keeps some random person who owns a gun from taking one of these down, exactly?
:)
Gravity.
It has been called an "unforgiving motherfucker" by the walker-bound elderly, but the fact is, only gravity can protect our prescious airships from the terrorists who seek to destroy our way of life.
Let's suppose you've got a nice powerful 50 cal that fires at 2000 feet per second.
physics tells us that it'll take 2000 feet per second / 32 feet per second per second = 62.5 seconds to reach it's max height.
Then we can figure out how high that is with this equation:
distance = initial speed * time - ( 1/2 ) * acceleration * time^2
2000 * 62.5 - 0.5 * 32 * 62.5^2
125000 - 62500
== 62500
So your bullet will turn around roughly a mile short of the target.
You're right that helium escapes into space, at the surface temperature of the Earth, helium atoms have escape velocity (or close enough to it, accounting for the Maxwellian velocity distribution). So unearthed helium eventually escapes away from the planet. Hydrogen does as well, but I believe all other gases are heavy enough to remain bound.
I work in cryogenics here in the USA, and we routinely let helium gas escape into the air (eg, when inserting a room-temperature insert into a dewar of liquid helium). In Europe, from what I understand, most labs collect this boiled-off helium gas, and somewhere else they can re-liquefy it. Don't know what Canada, South America, Asia, or other places do, though.
One of my professors was explaining why we don't recycle the helium here in the USA. He said this is because helium is typically 'mined' at the same time as companies dig for oil and natural gas. Thats where the large helium deposits are found. The market for helium is so small that petroleum companies want to just let the helium gas escape, it's not worth their time to collect/purify/sell it.
The NSF, however, doesn't want this to happen (environmental issues and maybe to capture more of the rare He3 too), and was able to influence American-based petrol companies to collect and sell the helium instead of wasting it. In exchange the oil companies need to have enough of a helium market to do this, so that's why Helium gas is typically not recycled in the USA, so the oil companies will sell it instead of let it go.
As one side note - you need to use alot of He gas to make recycling it cost effective, so only a few institutions in the USA recycle He. In Europe the density of such labs is much higher, so it's easier for Europeans to recycle this. Not sure if He is recycled in South America or Asia, though.
So unless my professor is entirely bullshitting, the problem stems not only from many labs not recycling He, but from global petrol companies letting the He gas free instead of capturing it themselves. But as to your original question, there shouldn't be significant amounts of helium used in the airships compared to global supply.
make world, not war
We had plenty of helium then too. We wouldn't sell it to Germany because they had used Zeppelins to bomb London only 20 years before.
In those days, essentially all the helium in the world came from a hole in the ground outside Amarillo, Texas. It sits atop a big deposit of alpha-emitting ores, and every alpha particle sooner or later picks up two electrons, which makes it a helium atom. Helium was a big contributor to the economic development of the Texas Panhandle, which is why Amarillo is the only city with a monument to an element.
rj
Sorry, had to be said.
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You don't know all the positions of the government's satellites, why should you care about the blimps? And no, this isn't a tinfoil hat theory. Do you have any idea how many payloads are launched each year and described only as a "4000 kg to 6000 kg chunk of mass"?
... lmao ... think again. It's amazing the things you learn when you get into defense - and then it's funny seeing people squirm about something so trivial as a blimp floating along the coast.
Remember that satellite photo of the 9/11 ground zero area that could show vehicles and people? Think that's the best the government has
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
You'd be surprised what you can do with a little knowledge of physics.
Let's start designing a really good airgun. Or actually describe something which already exists.
First let's remember that you can only accelerate something via gas pressure to the speed of the gas mollecules themselves. Any faster, and the gas will literally be left behind.
So we'll want to maximize the velocity of those mollecules. The energy of one of those little buggers depends on temperature. But that's not our ticket. Our ticket is noting that at the same energy (hence temperature) the less mass you have, the more velocity is needed to achive that energy.
Hence, you'll want a very lightweight gas. Hydrogen or helium will do just nicely. So we'll build a hydrogen gas gun.
Now to compress the helium. Well, have the airgun's barrel, which is a thin tube. We'll also have a much larger tube with a piston to compress the gas.
Think: a syringe. We push the piston in the large syringe body, to shoot a tiny sting through the tubular needle. Of course, at a much larger scale.
We'll also need to push the piston really hard, to create a lot of pressure. An explosion will do that just nicely.
It's really much like a conventional gun with a twist. Instead of the (relatively) heavy gasses from the explosion directly pushing the projectile, we compress hydrogen with them and the hydrogen pushes the projectile.
It's a very large device and very much a one shot gun, because reloading it takes ages. As such fairly useless against either ground targets or aircraft. (Against aircraft you really want something which sprays a lot of bullets.)
It also accelerates a dart to miles per second velocities. Theoretically, you could shoot at a sattellite in low orbit with it, except you would need to aim very very well. However, to punch a hole through a huge stationary blimp, it's perfect.
It's also low tech. A lot lower tech than rail guns. Any third world country could build one, if they wanted to. Heck, theoretically you could build one in your back yard. (But in practice the police would want to know about all those explosives you're buying.)
Until now, well, there was no problem for which it would be a solution. Now those blimps are just the problem for it.
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